bredgen essay plan

• Brengden AO1

  AIM: investigate aggression in MZ and DZ twins to find - extet social and physical aggression is explained by genetic an environmental influences

  METHOD: twin study, correlation study, 234 pairs of twins from QNTS used

  PROCEDURE: ratings taken from 1- teachers who rates social and physical aggression of each child on a three point scale and 2 - peer ratings where classmates chose three photos from a book of all children who best matched descriptions of behaviours. correlation test then performed

  RESULTS: higher correlation between MZ pairs on physical aggression than DZ airs in teach and peer ratings, social aggression roughly equally correlated in both. teachers rated boys more physically aggressive and girls more socially,, girls rated boys more on both

  CONCLUSION: physical aggression more genetic, social is more due to environmental factors. physical aggression may lead to social aggression but not the other way round
• Brendgen AO3 strength

  reliability - strong due to use of standardised measures of aggression ratings eg rating scales and descriptive rating = consistency in how data measured

  CA: may have been differences in how teachers interpreted the scales = some subjectivity = lowers reliability

  SW: overall though internal reliability is high due to standardised methods
• Brendgen AO3 weakness

  generalisability - age group of 6 yrs old = specific = can't assume aggression would be the same in other age groups = not generalisable, conducted in quebec = individualistic culture = aggression may be more overt in demonstrating aggression = not representative of other cultures and wider population

  CA: large sample of 234 pairs of twins = aggression could be measured in a range of children in the target population

  SW: although large sample, findings can't be generalised to wider pop due to age range and culture